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| VOLUME 80 (2004) | ISSUE 11 | PAGE 831 |
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Amorphization of cuprite, Cu 2O, due to chemical decomposition under high pressure
V. V. Sinitsyn, V. P. Dmitriev+, I. K. Bdikin, D. Machon+, L. Dubrovinsky*, E. G. Ponyatovsky, H.-P. Weber
 Institute of Solid State Physics RAS, 142432 Chernogolovka, Moscow District, Russia +Group "Structure of Materials under Extreme Conditions", Swiss-Norwegian Beam Lines at ESRF, F-38043 Grenoble, France *Bayerisches Geoinstitut, Universitat Bayreuth, D-95440 Bayreuth, Germany LCr/IPMC/FSB, Swiss Federal Institute of Technology, CH-1015 Lausanne, Switzerland
PACS: 74.50.+r, 74.80.Fp
Abstract
Using synchrotron radiation and a diamond-anvil cell, a structural study of the phase transformations in Cu2O is carried out from diffraction data obtained in-situ while heating at a pressure of 30 GPa. Around 140 °C we observe a transition of Cu2O to an amorphous state, with the amorphous state persisting to about 260 °C. Further heating up to 400 °C yields at first a nanocrystalline two-phase mixture of Cu+CuO; then with prolonged heating at 400 °C full crystallization of this mixture. The present structural data are the first experimental evidence of solid state amorphization under high pressure as an intermediate stage of the high-pressure decomposition of complex compounds. |